Local telephone calls have, for many years, been effected by dialing a seven digit code. At one time, all long distance calls were handled by "long lines" operators who more or less manually established a routing for a given call. However, since the late 1950s, direct dial long distance calling has been widely used. Directly dialed long distance calls involve the dialing of a first prefix, typically "1", to indicate to the telephone company apparatus that a long distance call is contemplated, then dialing a second prefix, the three digit area code, before the local seven digit number of the called party is dialed. In this manner, a long distance call can be carried out without the intervention of an operator. Variations of this process, typically dialing longer strings of numbers, permits international long distance direct dialing.
When this system was established, largely under the auspices of American Telephone and Telegraph Company, it was believed that the allocation of possible telephone numbers (including area codes) was adequate to handle all demand for many years. However, it is becoming evident that such is no longer the case. In particular, the remarkable proliferation in dedicated line demand for fax machines and the like, and, especially, for modems which may be used, inter alia, for connecting a computer to the Internet and other networks, has pushed the allocation of available lines, notwithstanding the application of various technological advances, to near the limit possible with the current system.
One technological advance which promises to alleviate this problem for a number of years is to require a calling party to dial the area code of a called party even when the two parties are within a common area code. Thus, one would be required to dial a ten digit code even if the called party is next door. It will be readily apparent that this change will be highly inconvenient to many persons who wish to continue the use of the traditional seven digit dialing for local calls. Accordingly it will be understood that a method and apparatus which, in such a contemplated modified telephone dialing system, permits the ongoing use of standard seven digit dialing for routine local calls would be highly desirable, and it is to this end that the present invention is directed.